Purification of acetic anhydride



'; Patented Dec. 25, 1 928.

U T DgSTA Es wee PATaNT oFFic WILLIAM PEARSOLI SKERTGHLY, SPONDON, NEAR DERBY, ENGLAND, ASSIGIIOR TO GELANESE CORPORATION OF AMERIOA, A CORPORATION OF DELAWARE.

I crunlrrosrron or Learn: ANHYDBIDE.

mi mam-lg. a pucaumiaiea raich 2s, 1926, seria1no.97,44s, and in Great Britain February 13, 1926.

This immatu e to the pnfiacau'on of acetic anhydride.

I have found that acetic anhydride .con-- taining .-sul-phur or sulphur compounds can :5 be purified by'treatinent with, s'odiuin' acetate,or, oth'e'r'alkali metal acetate'or earth alkali metal acetate orother metallic-acetate,and chlorine, orby treatment with two or more of such acetates and chlorine.

In carrying out the invention the acetate or acetates" are preferably used anhydrous and they are preferably employed in pow dered form. i

In carrying out mix the acetic. anhydride, at' any temperature up' to'its boiling point, with sodium .or other acetate or with t 0 or more acetates, and

then introduce chlorine: in quantities-suiticient'to combine with any reactive'sulphur or sulphur compounds, after which the acetic anhydri'de may be distilled and collected 1n any suitable way. The following example serves to. illustrate one method of executing the present inven tion, it bein Y onlyhy way of illustration and is in no, way

' limitative.

Ex mp e.

' 60 parts by weightof finely powdered'anhydroussodium acetate are placed in 1,000

- parts'by weight of uupurified acetic anhydride (containing, for example, 3 parts by weightot sulphur) andthen about 7 parts 3 by weight of chlorine are introduced into the mixture while the mixture is stirred continuously. After mixing thoroughlyfor about half-an hour, the acetic anhydride is distilled and collected inany suitable manner.

Process for the purification of acetic anthe' inyention I may first.

understood that thisds' given" What I claim and desire to secure by Lethydride containingsulphur or sulphur. compounds, comprising treating the same with chlorine and with at least one metallic acetateL 'anhydride containing sulphur or sulphur compounds, comprising treating the same with chlorine and with at least one alkali V metal'acetate. Y

purification of acetic 3. 'Process for the anhydride containing sulphur 'or sulphur compounds, comprising treating the same.

:rvith chlorine and'withsodium' acetate.

4.: Process for the-purification of acetic anhydride containing sulphur or sulphur compounds, comprising treating the same with chlorine; and with at leastone anhydrous metallic acetate, i

5. Process for the purification of acetic anhydride containing sulphur or sulphur compounds, [comprising treating the same with chlorine and with kali metalacetate.v

. 6. Process for the-purification'of acetic an-v' hydride containing sulphur orsulphur compounds, comprising treating the same with I chlorineand' with anhydrous sodium acetate,-.-

7 Process for the purification of acetic anhydride containing sulphur or sulphur compounds, comprising mixing the samewith at least one metallic acetate and then introducing chlorine into the mixture,

Process forthe purification of acetic anh'ydride containing sulphur or sulphurconipounds, comprising mixingthe same with at least one metallic acetate, then introducing lin -the acetic anhydride. V n testimony whereof, I have hereunto subscribed my name.

. -.WI.LLIAM PEARSON 'SKERTCHLY.

at least. one anhydrous al chlorine into the mixture and finally disti l-,

2. Process for the purification of acetic 

